Improvement in apparatus for amalgamating gold in tailings



'UNITED STATEs PATENT OFFICE.

THOMAS A. PRATT, OF MARYSVILLE, CALIFORNIA.`

IMPROVEMENT IN APPARATUS FOR AMALGANIATING GOLD IN TAILINGS.

Speciication forming part of Letters Patent No. 121,296, dated November 28, 1871 antedated November 11, 1871.

To all whom it 'may concern:

Be it known that I, THOMAS A. PRATT, of Marysville, cormty of Yuba, State of California, have invented Improvements in Gold-Saving Apparatus;V and I do hereby declare the following description and accompanying drawing are sufficient to enable any person skilled in the art or science to which it most nearly appertainsito make and use my said invention or improvements without further invention or experiment.

My invention relates to an improved device for concentrating and amalgamating the precious metals by the use of which I am enabled to work tailings and a poor quality of ores profitably.

In order to explain my invention so that others can make and use the same, reference is had to the accompanying drawing forming a part of this speciiication, in which- A represents an iron vessel, near the bottom of which is a hopper-shaped spout, B, the small end of which is secured iirmly to the vessel. This spout is secured to the vessel A at an angle to its circumference, and serves to convey the pulp or tailings into the vessel. A vertical shaft, C, steps in a bearing in the center of the bottom of the vessel, and is supported at its upper end in a cross-bar, d, which passes across the top of the vessel A. The lower end of this shaft is provided with screw-threads, and carries a peculiarly-constructed wheel or series of wings. and is described as follows: c and f are two small disks, through the vcenter of which the lower end of the shaft O passes. These disks are placed at a distance apart, and have secured between them the radiating wings g, which extend a considerable distance beyond their circumference. h and i are two side disks of larger diameter than the disks e f, the whole being iirmly held on the shaft by nuts j, one upon each side of the wheel thus formed, and by means of which the position of the wheel upon the shaft can be adjusted. The angle of the wings on the lower disk h is such that the heel or lower portion will press down the surface of the quicksilver, and as they pass rapidly over it an ebullition of the Quicksilver will be produced, which mixes it thoroughly with the tailings and causes the heavier particles of metal to settle to the bottom, while the lighter portion is thrown to the upper surface of the upper disk between the oppositely-inclined upper wings, from whence it is gradually carried out over the top of the vessel A by the accumulation of light matter beneath it.

When used in connection with the quartz-mills the vessel should be placed at the foot of the sluices leading from the batteries.

The height of the fall which should be given 'to the tailings in order to drive the stirringwheel must be regulated according to the weight of sand and sulphurets containedin the tailings, so that the work of amalgamation will be thoroughly accomplished.

By the use of this machine tailings can be profitably worked. Rusty particles of gold which resist the usual method of amalgamation can also be saved by this machine.

The outer rims of the disks h i are slitted radially at a short distance apart, and each wing m thus formed is turned so as to stand at an angle to the central plate of the disks. The wings a, on the lower disks, are given an opposite angle to the wings m on the upper disk, and one of the radiating wings g passes across the space between each two opposite wings of the two disks.

The bottom of the vessel A is covered with quicksilver to the desired or necessary height, and the wheel on the shaft adjusted so that the lower disk h will bear gently upon its surface. If used in gravel or surface diggings I then make 'an opening across the bottom of an ordinary sluice-box, the size of which can be adjusted according to the amount of discharge. Through this opening' a portion of the tailings can pass into an under or lower sluice. From this lower sluice the tailings pass into the hopper-shaped spout B, and thence into the bottom of the vessel A. The force of the water and tailings striking the'vertical Wings g will cause the Wheel to revolve rapidly in the vessel.

Having thus described my invention, what I claim, and desire to secure by Letters Patent,is--

The vessel A, provided with the hoppershaped spout B, in combination with the adjustable stirring-wheel, composed of the disks h i, with their angular wingsm n and vertical dividing wings g, all constructed and arranged to operate substantially as and for the purpose above described.

In witness that the above-described invention is claimed by me I have hereunto set my hand and seal.

THOMAS A. PRATT. [1.. s] f Witnesses:

N. D. RIDENT,

OHAs. FAULKNER. 

